Grocery-delivery services are booming, and for good reason: it’s lucrative. Just five years ago, the grocery delivery market was a fledgling industry, and today, nearly one-quarter of American households rely on some form of grocery delivery...

The recent news concerning Amazon's acquisition of Whole Foods has been mesmerizing for many in the supermarket industry because — beyond possibly making Whole Foods sharper on expense controls and pricing — it communicated that Amazon...